1. Field of the Invention
The present invention relates to a bio isolator.
2. Description of the Related Art
A bio isolator, an isolator for bio research, a biohazard isolator or the like is a system having a sterilized workroom, in which operations that require a sterile environment, such as those involving biologically-derived materials obtained by cell culture, for instance, are performed. The sterile environment meant here is an environment substantially free of dust and germs such that it allows no entry of substances other than the materials used in the work done in the workroom. Among conventionally known technologies for such an environment is an isolator having a sterilization chamber which is connected to a workroom via a door and in which articles to be carried into the workroom are sterilized.
The workroom is equipped with a gas supply port and a gas discharge port. Air outside the isolator is supplied into the workroom through the gas supply port, and the air in the workroom is discharged through a gas discharge port. Generally, the isolator is provided with a particulate trap filter, such as a HEPA (High-Efficiency Particulate Air) filter, at the gas supply port in order to keep a sterile environment for the workroom, and the outside air is supplied into the workroom through the particulate trap filter. Also, a particulate trap filter is provided at the gas discharge port, and the air inside the workroom is discharged outside through the particulate trap filter.
Also, in the isolator, a sterilization treatment is conducted in the workroom and the sterilization chamber with a sterilizing material (sterilizing agent), such as hydrogen peroxide gas, sprayed into them.
Under the circumstances as described above, the present inventors have realized the following problems with the system:
In the above-mentioned sterilization treatment, upon completion of sterilization process, a process of replacing the sterilizing material in the workroom with air is carried out, in which the sterilizing material therein is decomposed by a catalyst while air is sent thereinto. At this time, if there is the sterilizing material adsorbed by the particulate trap filter, the replacement process will take a long time because it is not easy to remove the sterilizing material from the particulate trap filter. As a consequence, the process of sterilization as a whole takes a long time.
The isolator is of such design that work in the workroom cannot be started until the concentration of the sterilizing material is low enough to have no adverse effect on the articles to be processed. Besides, in the isolator, after the end of one operation in the workroom, a sterilization treatment is generally performed before the start of the next operation. Hence, if the work efficiency in the isolator is to be enhanced, it is necessary to shorten the time required by the sterilization treatment.